Fabrication of Nanostructured Cu matrix Nanocomposites by High Energy Mechanical Milling and Spark Plasma Sintering

Spark plasma sintering (SPS) is a sintering process that is capable of sintering work hardened powders in short times. This technique was used to fabricate bulk Cu and Cu-SiC nanocomposites. Pure Cu and mixed powders of Cu including 4 vol. % of SiC nanoparticles were mechanically alloyed for 25 h and then sintered at 750 ˚C under vacuum condition by SPS method. Microstructures of the materials were characterized using optical and scanning electron microscopes and x-ray diffraction patterns, and mechanical properties were evaluated by micro-hardness tests. The results showed density values of 8.69 and 8.30 g/cm3 and hardness values over 105 and 128 Hv for Cu and its nanocomposite respectively. The addition of nanoparticles retarded Cu matrix grain growth during SPS process and resulted in higher hardness of nanocomposite compared to non-reinforced copper.